This invention relates to an electromagnetic assembly which is used for locking a switch in its operative position for operating, for example, the car window, the sun roof, the automatic antenna and the like, or locking the switch normally in its "on" position and releasing the switch from the lock position in the event of or overvoltage in order to protect the circuitry from being damaged.
Heretofore, the relay for maintaining the energized state of the circuit or of the plunger of a solenoid utilized for performing a required function has been separated from the relay used for detecting overcurrent and overvoltage in order to break the circuit.
For example, when the car power window is to be opened or closed by one-touch operation or by instant switch-on operation, the following devices were required: (1) relay for detecting the state of "switch-on" in order to continue supplying power to a motor and (2) an electronic circuit, a relay, etc. for detecting overcurrent due to motor-lock when the motor is locked and removing the self-holding state maintained by above mentioned relay when the window completes the opening or closing operation.
Therefore, high costs, complicated structure of circuitry, etc, to large installation space, use of the additional electronic circuit, the relay and the like resulted in inherent disadvantages to the prior art devices.